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Tiger Predation
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 (11-27-2015, 04:11 PM)Shardul Wrote: Only 3 of the 11 places you listed actually have wild elephant populations. This is similar to your comment on how gaurs constitute a low percentage in the tiger's diet, without ever considering that gaurs are mostly absent in the areas where most tiger research occurs. Absolutely, and for sure the abundance of both predator and prey in a given area and their encounters will determine the interactions between them, nowadays the world population of gaur ( less than 25000) , Banteng ( less than 8000 ) , and wild water buffalo ( less than 4000) means that their distribution is patchy and their importance as a component in tiger feeding ecology is less than what it was a hundred or two hundred years ago. Jacob's index shows the preference of a predator for a particular prey according to availability and expected encounter rates and if we are discussing gaur then it is most common and preferred in the west Ghats ( Bandipur and Nagarahole ) whereas Sambar for example is highly selected in most of areas. Tigers as intelligent and successful predators will always select a prey that is: available (no need to spend a lot of energy locating it) , large enough to provide several meals (to be energetically profitable), fairly easy to subdue and kill, and not likely to pose serious risk of injury and hence you see the importance of cervids and wild boar throughout the tiger range and bovids in certain areas like the west Ghats and the western forest complex in Thailand. (11-27-2015, 09:09 AM)Brehmji Wrote: By all respect towards science and your scientific and personal research/experience, but not everything can't be (and dont has to be in some case...) scientifically verified to consider if it's true or not. My main point is that when something is described in a scientific, verifiable, reproducible way then it is a fact, does science nowadays describe all facts? NO, and it will never will because the universe is immense and amazing and there are always exceptions to every rule. Do I accept videographic , photographic evidence, and the personal accounts of reliable people? Yes of course. If Corbett saw the incident himself I would accept it 100% but you see the logic in disputing that. The one thing that amazes me about tigers ( and lions for that matter) is their awesome ability to surprise me with new behavior that is different than the known facts over and over again, ( and scientists are the first to update their work to reflect new findings) they are highly individual animals with remarkable behavior. At the same time I am not happy about the supposition of some members on this blog that juvenile elephants are just oversized babies that are easily killed, a five year old elephant is bigger and likely stronger than all terrestrial mammals except other elephants and when a tiger or a lion succeeds in killing it, it is a great feat of strength and predatory skills.
11-29-2015, 10:37 PM
( This post was last modified: 11-30-2015, 06:38 AM by tigerluver
Edit Reason: Removed excessive quote, added tag
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Thank you @peter as always your posts are informative, enriching, and well-written.
I believe that Shoshani and Eisenberg referred to these accounts in their excellent work on Asian elephants in 1982, so the possibility of such rare attacks is not discounted by me altogether, the point is that this a very rare and poorly documented behavior that there is no value in discussing it, as you said nowadays biologists know enough about predators and are more concerned with their conservation and survival versus documenting once in a lifetime events ( which when witnessed and documented is still amazing)  (11-29-2015, 10:24 PM)Dr Panthera Wrote: My main point is that when something is described in a scientific, verifiable, reproducible way then it is a fact, does science nowadays describe all facts? NO, and it will never will because the universe is immense and amazing and there are always exceptions to every rule. I don't think anybody is discounting the idea that a juvenile elephant isn't a hard prey to kill. But I will be the 1st to say that I certainly don't think an elephant younger than 4 or so is harder prey than a bull buffalo or rhino. I look at the morphology of them, being closer to the ground, more practical defense towards prey and testosterone boost that the juveniles just won't have yet make the two species mentioned more deadly towards the predators than a juvi elephant. I look at elephants defense and think that they're more guarded for defense against each other over predatory defense since their size will be much more of a deterrent than their weapons when prey is thinking of attacking them. Not that their weapons aren't formidable but you are for more likely to get trampled than whacked with a trunk or tusks from the accounts I see. I will delve into my personal ideas more when I have time tomorrow. But I definitely see where you're coming from as well. 
Tag each other or limit the chain of quotes to reply large quote, not super-quote please. If you don't mind I'll do this fix for all the current posts.
To remove extra quotes from a quote, delete everything after the first quote initiation code and before the part of the quote you'd like to keep. (11-27-2015, 04:11 PM)Shardul Wrote:(11-27-2015, 01:53 AM)Dr Panthera Wrote:(11-21-2015, 05:44 AM)Pckts Wrote: You aren't comparing apples to apples. To generalize one statement compared to another is wrong. There are multiple people who heard it go on all night, to simply say, "nope, never happened" because they didn't go to school is wrong. Exaggerations happen, of course, but there is nothing here that isn't outside of the realm of normal. Tigers have preyed on elephant, absolute fact. Tigers have hunted as pairs or families, fact. So because it was against a Bull you want to say no? Respectfully : Nagarahole,Bandipur,Bardia, Huai Kha Khaeng, and Way Kambas all have resident elephant populations , Chitwan get transient ones from India across the border (mainly males) so six areas of overlap. There is a good amount of tiger research in areas where gaur exists ( e.g. Bandipur, Nagarhole, Kahna, Chitwan, and HKK from the mentioned areas and also in Manas, Kaziranga, and Malaysia among others. Gaur is represented in 15 studies out of the 25 I mentioned with contribution to tiger diet ranging from 0 to roughly 40%. 
@Dr Panthera, please notice that too many quotations could mess up the interface.
Maybe you could tag the person that you want to respond in the next post.
"Respectfully : Nagarahole,Bandipur,Bardia, Huai Kha Khaeng, and Way Kambas all have resident elephant populations , Chitwan get transient ones from India across the border (mainly males) so six areas of overlap. There is a good amount of tiger research in areas where gaur exists ( e.g. Bandipur, Nagarhole, Kahna, Chitwan, and HKK from the mentioned areas and also in Manas, Kaziranga, and Malaysia among others.
Gaur is represented in 15 studies out of the 25 I mentioned with contribution to tiger diet ranging from 0 to roughly 40%. " Gaur historically occurred throughout mainland South and Southeast Asia, including Vietnam, Cambodia, Laos, China, Thailand, Peninsular Malaysia, Myanmar, India, Bangladesh, Bhutan, and Nepal. Today, the species is seriously fragmented within its range, and regionally extinct in Sri Lanka.[1] Gaur are largely confined to evergreen forests or semi-evergreen and moist deciduous forests, but also occur in deciduous forest areas at the periphery of their range. Gaur habitat is characterized by large, relatively undisturbed forest tracts, hilly terrain below an altitude of 5,000 to 6,000 ft (1,500 to 1,800 m), availability of water, and an abundance of forage in the form of grasses, bamboo, shrubs, and trees. Their apparent preference for hilly terrain may be partly due to the earlier conversion of most of the plains and other low-lying areas to croplands and pastures.[12] They occur from sea level to an altitude of at least 2,800 m (9,200 ft). Low-lying areas seem to comprise optimal habitat.[13] In Vietnam, several areas in Đắk Lắk Province were known to contain gaur in 1997.[14] Several herds persist in Cát Tiên National Park and in adjacent state forest enterprises.[15] The current status of the gaur population is poorly known; they may be in serious decline.[1] In Cambodia, gaur declined considerably in the period from the late 1960s to the early 1990s. The most substantial population of the country remained in Mondulkiri Province, where up to 1000 individuals may have survived in a forested landscape of over 15,000 km2 (5,800 sq mi).[16] Results of camera trapping carried out in 2009 suggested a globally significant population of gaur in the Mondulkiri Protected Forest and the contiguous Phnom Prich Wildlife Sanctuary.[17] In Laos, up to 200 individuals were estimated to inhabit protected area boundaries in the mid–1990s.[18] They were reported discontinuously distributed in low numbers. Overhunting had reduced the population, and survivors occurred mainly in remote sites. Fewer than six National Biodiversity Conservation Areas held more than 50 individuals. Areas with populations likely to be nationally important included the Nam Theun catchment and the adjoining plateau.[19] Subsequent surveys carried out a decade later using fairly intensive camera trapping did not record any gaur any more, indicating a massive decline of the population.[1] In China, gaur occur in heavily fragmented populations in Yunnan and southeast Tibet. By the 1980s, they were extirpated in Lancang County, and the remaining animals were split into two populations, viz. in Xishuangbanna–Simao and Cangyuan. In the mid-1990s, a population of 600–800 individuals may have lived in Yunnan Province, with the majority occurring in Xishuangbanna National Nature Reserve.[1] In Thailand, gaur were once found throughout the country, but less than 1,000 individuals were estimated to have remained in the 1990s. In the mostly semi-evergreen Dong Phayayen – Khao Yai Forest Complex, they were recorded at low density at the turn of the century, with an estimated total of about 150 individuals.[20] In Bangladesh, a few gaur were thought to occur in the Chittagong Hill Tracts, Sylhet, and Mymensingh areas in the early 1980s, but none had been seen in Pablakhali Wildlife Sanctuary situated in the Hill Tracts since the early 1970s.[21] Individuals from Mizoram and Tripura cross into Bangladesh.[13] In Bhutan, they apparently persist all over the southern foothill zone, notably in Royal Manas National Park, Phibsoo Wildlife Sanctuary and Khaling Wildlife Sanctuary.[13] In Nepal, the gaur population was estimated to be 250–350 in the mid-1990s, with the majority in Chitwan National Park and the adjacent Parsa Wildlife Reserve. Population trends appeared to be relatively stable.[1] The Chitwan population has increased from 188 to 296 animals in the years 1997 to 2007; a census conducted in Parsa Wildlife Reserve confirmed the presence of 37 gaur in May 2008.[22] In India, the population was estimated to be 12,000–22,000 in the mid-1990s. The Western Ghats and their outflanking hills in southern India constitute one of the most extensive extant strongholds of gaur, in particular in the Wayanad – Nagarhole – Mudumalai – Bandipur complex.[23] The populations in India, Bhutan and Bangladesh are estimated to comprise 23,000–34,000 individuals.[13] Major populations of about 2,000 individuals have been reported in both Nagarahole and Bandipur National Parks, over 1,000 individuals in Tadoba Andhari Tiger Project, 500–1000 individuals in both Periyar Tiger Reserve and Silent Valley and adjoining forest complexes, and over 800 individuals in Bhadra Wildlife Sanctuary.[1] There hasn't been any seen guar in kaziranga for quite some time, I read that there were some there but have never seen any photographed in any recent years. Even if they do still exist, their numbers would be extremely low. The malayasian population has no tigers so they obviously cannot hunt them there. Basically the only places where guar and Tigers co exist at any real number is Bandipur, Kahna, Tadoba and Chitwan but since the chitwan tiger population was decimated and has only recently had tigers reintroduced its not like you can get any real data from that. At the end of the day, Bandipur, Kahna and Tadoba have guar predation from tigers, often. This thread a lone can show over 20+ individuals in the past year that have had tiger predation on Guar in those 3 areas. I would say its most often in Tadoba from what I have seen. But what does that mean? You would need to ask these questions: -Gaur population in the areas? -Access of these areas via tourists and naturalists for Study -Tiger population and protection in these areas? etc. We cannot lump in studies where these animals don't coexist or their numbers have been decimated by hunting and try to use it as an all encompassing result. Like its been stated, that is a skewed result that needs to be corrected when trying to use certain examples as fact. 
@Dr Panthera
Yes. But in what numbers? If a forest is abundant in deer but has a scant gaur population, then the tiger's diet will obviously reflect that. It's a question of availability, not ability. Whether it is about tigers and gaurs or tigers and elephants, you only need to include areas where population of both animals is very healthy. This criteria is fulfilled only by the Southern Indian forests.
As Pckts elaborated gaur current distribution has shrunk considerably and their numbers are quite low making the likelihood of tigers encountering them and preying on them less and less, the only areas where there is high overlap are the Southern Ghats ( Bandipur, Nagarahole ) and The Western Forest Complex in Thailand and to lesser degree in other areas.
The best analysis of tiger prey preference was conducted by Matt Hayward et al. and showed that gaur were potential tiger prey in eight study areas and actual prey in five areas, tigers hunt gaur according to their availability they neither prefer them nor avoid them, Jacobs index showed slight avoidance of gaur -0.3 and ..compare that with the strong selection for large deer ( sambar 0.35 , red deer 0.29, Barasingha 0.27) and wild boar 0.34. The fact remains that tiger over their entire distribution depend on large cervids and wild boar as their staple diet, supplementing it with smaller deer, bovids, and livestock in certain areas. (12-01-2015, 04:08 AM)Shardul Wrote: @Dr Panthera Availability and selection ( Barasingha is rare in most areas but is always sought by tigers, Sambar will always be more targeted than the larger gaur or the smaller chital ) , ability is not the issue tigers are supreme predators and can take most available prey items it is what they can encounter and subdue with the maximum energetic benefit and tolerable risk. And I agree with you that large numbers of all three animals (tigers, gaur, elephants) is only seen in the Western Ghats, see my post of tiger prey preference as discussed by Hayward et al. it studies the prey preference of tigers all over its range, it lists 8 areas where tigers and gaur coexist and 5 areas where tigers prey on gaur.
Other reasons for the declining numbers of gaur is the decimation of many of their populations in the hoof and mouth disease and hybridization with domestic cattle ( gayal/mithun ).
ON GENERAL RULES AND EXCEPTIONS
I followed the proceedings and decided for another post, this time to support the points made by Dr. Panthera. Forums and posters Posters usually are interested in a particular animal. In this forum big cats are quite popular. Those interested in them often focus on exceptional animals and remarkable feats. I understand, as biologists have neglected morphology and exceptions to an extent. This, of course, opened the door for those keen on exceptions. Exploring limits seems to be in the genes of many. I also plead guilty, but would like to add that exploring limits seems to be needed to get to the core of things. Same for specialisation. Maybe this is what we all want. The natural world is an unknown, but very interesting world and it opposes that of humans in many ways. Although disregarded, my take is we can learn a lot if we are prepared to have a look. Exceptions Big cats are large, well armed and very capable specialists and quite something to behold. For many of us, they are 'Monsters of God'. We need them and wouldn't mind seeing a few examples of their might every now and then. There are plenty of them, even today. In Africa, lions hunt elephants, hippos and the big Cape buffalo. In South-America, jaguars tackle caimans larger than themselves. We know that leopards are able to pull animals of similar weight in a tree. And then there is the tiger. Imagine a 10.9, 705-pound tiger going for the howdah (a height of 15 feet). It really happened in Nepal. That giant male was cornered, but there are more cases known of tigers fighting elephants. We also know they hunt large herbivores. One of them, known as 'The killer of men', only hunted very large wild male buffalos. He was so strong that the broke their neck each and every time. In nearly every case, the horns of the bull stuck into the ground. Really happened. Ask B. Berg. R.C. Morris wrote about fights between male tigers and male gaurs in southern India. Rare incidents, they were, but not as uncommon as one would think. There are more remarkable feats and all of them have been documented by those who lived most of their life in the forest following and hunting tigers. Realible witnesses in my book, but opinions differ. Patterns Now imagine you're a biologist. You move to southern Asia to study tigers. What you will see is plenty of forest, but no large animals and no tigers. Not anymore. They send you to a remote region in, say, Thailand. A region that still has a few tigers. You do a project and when you're done, you want to have contributed. In order to get there, you have to describe patterns and address problems. In most, if not all, documents produced by biologists, you will find info on habitat and species conservation, advice on anti-poaching teams and an evaluation of the effect of measures taken some time ago. The rest is up to others. In the end, it all boils down to money and the political will to act. How find patterns? You can go to the local butcher or you can ask someone who knows how to answer the question on what tigers eat. Let's assume you employ a trained specialist. After five years, he concludes that tigers eat small to moderate-sized animals. You than compare the region you studied to others and discuss the problems you encountered. When done, a peer-reviewed document with patterns, tables, conclusions and recommendations will be published. These documents are the only valid tools biologists have. To conclude If tigers are to be saved, research, knowledge, solid advice on how to overcome problems and, in particular, political will and money are needed, not anecdotes on enormous tigers fighting bull elephants once every two decades. Based on what I read, Dr. Panthera is well-informed and his conclusions are sound too. This, no offence meant (and taken, I hope) is what is needed on a forum loaded with members interested in exceptional stories and exceptional animals. Balance is a thing of beauty too. But I promise to produce a few more stories, as this is a forum and finding stories is my trade. And they are there. Plenty of them, in fact. I recently found an old magazine used by Dutch hunters in Indonesia. Very interesting. I also found a number of interesting stories. Next on the list are the natural history museums of Bonn, Budapest and, if possible, Vladivostok and Chabarowsk. I am contemplating visiting some of the former Sovjet-Union republics as well. What we see on this forum is what we see in real life as well. Those interested in new developments and new techniques are leading the way, whereas those with one leg in the previous centuries struggle to keep up. Both camps often clash and the struggle will never really end, nor should it. The intention should be to select the best books, documents and tools of both camps and use them to continue exploring our planet without sacrificing too much. It is a place of beauty and if we forget about that, chances are she will tell us in no uncertain way that we need to change a few things. All living creatures demand respect. With all living creatures, you mean the forests, the oceans, the air we breath and the planet accomodating us as well? Yes. Research and exploration is real nice, but there's something more important. Those who walked the forests and sailed the oceans now, but they often keep to themselves. Dersu, however, told us loud and clear. We didn't take him serious, but we should have ('Dersu the trapper', V.K. Arseniev). (12-01-2015, 04:53 AM)Dr Panthera Wrote: As Pckts elaborated gaur current distribution has shrunk considerably and their numbers are quite low making the likelihood of tigers encountering them and preying on them less and less, the only areas where there is high overlap are the Southern Ghats ( Bandipur, Nagarahole ) and The Western Forest Complex in Thailand and to lesser degree in other areas. Do you have access to the Hayward PDF? I'm curious if the predation is broken down by Tiger: age, sex and location and to compare the prey animals population and distribution to where the study takes place. Thanks 
Here is the document @Pckts (attached document).
After reading the paper again, I found several problems, specifically with the range of 60-250 kg, which is based in the weights of "Walker Mammals of the world" (more to come in this point) and a graphic about gaur depredation that I found weird, in comparison with the other ones. Maybe @Dr Panthera and @tigerluver can give us a light on this. |
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